极薄煤层半煤岩巷道切顶成巷矿压规律研究

Mine pressure law of self-forming roadways by roof cutting in semi-coal rock roadways of extremely thin coal seams

针对禾草沟二号煤矿1105工作面回风巷出现的矿压显现异常、支护困难等现象,结合矿井实际情况,确定采用沿空留巷支护技术。通过数值模拟和现场实测相结合的方法对切顶成巷矿压规律进行研究,研究结果表明:切顶留巷后,巷道顶板垂直应力明显下降,工作面回采过程中,顶板应力变化呈单峰分布,工作面超前支承应力影响范围大于60 m,工作面侧向支承应力影响范围约为60 m,当工作面回采到90 m时,巷道顶板垂直应力变化达到最大。根据矿压监测结果,薄煤层切顶爆破之后,恒阻锚索受力明显减小,成巷效果良好,恒阻锚索和巷道围岩变形均呈现“稳定—快速—缓慢—稳定”的变化趋势。巷道顶底板最大变形位置为巷道中部,顶板在工作面回采110 m后达到稳定状态,底板在工作面回采80 m后达到稳定状态。

To solve the problems of mine pressure anomaly and difficult support at No.1105 working face of Hecaogou No.2 Coal Mine,based on the in-site situation,gob-side entry retaining was employed.We studied the mine pressure law of self-forming roadways by roof cutting on the basis numerical simulation and field measurement.The research results show that the roof vertical stress of retained roadways has a significant decrease after roof cutting.The roof stress varies in unimodal distribution during face mining.When the influence of the advance abutment stress of the working face is more than 60 m,and that of the lateral abutment stress is about 60 m.When the working face is recovered to 90 m,the roof vertical stress change reaches the maximum.According to the results of mine pressure monitoring,after roof-cutting blasting in thin seams,the stress for the constant anchor cable was significantly reduced,and the effect of roadway forming was favorable.The deformation of the constant anchor cables and wall rock of roadways showed a trend of“stable-fast-slow-stable”.The maximum deformation of roof and floor is in the middle of the roadway.The roof recovery reaches stable after 110 m,the floor does after 80 m.